ACT 600105 ProLite Xact Flywheel ACT's lightest flywheel is designed for improving engine response, strength, and affordability CAD designed, CNC machined, and computer balanced for quality and precision; machined slots provide the lowest inertia One-piece forged Chrome-moly is stronger and more durable than billet steel, aluminum, or cast iron Integral ring gear is induction hardened for maximum gear life 90 day limited manufacturer's warranty